Treatment using herpes simplex virus

A kit of parts for use in treating a tumour in a human patient by combination therapy, said kit comprising a first container containing an herpes simplex virus (HSV-1) and a second container comprising a pharmaceutical, wherein the pharmaceutical is an activatable nitroreductase (NTR) prodrug and the HSV-1 genome encodes an expressible nitroreductase polypeptide capable of converting the activatable NTR prodrug to a therapeutically active pharmaceutical, and wherein the HSV-1 comprises a deletion, addition, substitution or insertion in each ICP34.5 gene, the kit further comprising instructions for the therapeutically effective administration of said HSV-1 and/or pharmaceutical to a human patient in need of treatment at an extratumoural location in order to treat the tumour, and wherein the tumor is a type that is capable of being treated with an alkylating agent.